export default {
  namespaced:true,
  state:() => ({
    // 购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')  
  }),
  mutations:{
    addToCart(state,goods){
      const findResult = state.cart.find((x) => x.goods_id === goods.goods_id)
      
      if(!findResult){
        state.cart.push(goods)
      } else {
        findResult.goods_count++
      }
      
      this.commit('m_cart/saveToStorage')
       
    },
    
    saveToStorage(state){
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    
    //更新购物车中商品的勾选状态
    updateGoodsState(state,goods){
      const findResult = state.cart.find(x=>x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_state = goods.goods_state
        
        this.commit('m_cart/saveToStorage')
      }
    },
    // 更新商品的数量
    updateGoodsCount(state,goods){
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(findResult){
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    // 根据id删除对应的商品
    removeGoodsById(state,goods_id){
      state.cart = state.cart.filter(x=>x.goods_id !== goods_id)
      
      this.commit('m_cart/saveToStorage')
    },
    // 更新购物车中所有商品的勾选状态
    updateAllGoodsState(state,newState){
      // state.cart.forEach(x=>x.goods_state = newState)
      state.cart.forEach(x => x.goods_state = newState)
      
      this.commit('m_cart/saveToStorage')
    }
    
  },
  
  getters:{
    // 购物车中所有商品的总数量
    total(state){
      // let c = 0
      // state.cart.forEach(x=> c += x.goods_count)
      // return c
      
      return state.cart.reduce((total,item)=> total += item.goods_count,0)
    },
    // 购物车中已勾选商品的总数量
    checkedCount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,item) => total += item.goods_count,0)
    },
    // 已勾选商品的总价格
    checkedGoodsAmount(state){
      return state.cart.filter(x=>x.goods_state).reduce((total,item)=>total += item.goods_count * item.goods_price,0).toFixed(2)
    }
    
  }
  
}